Author Topic: Bell H13CX Coaxial Helicopter  (Read 7721 times)

0 Members and 1 Guest are viewing this topic.

Offline frank2056

  • Wears a suit and tie when browsing What-If
  • Needs A Life Outside What-If
  • *****
  • Posts: 1259
    • My web page
Bell H13CX Coaxial Helicopter
« on: October 24, 2010, 06:30:56 pm »
I have a couple of the old Revell 1/35 scale H-13 Sioux helicopters in the MASH boxing. They were cheap and fairly nice, although the tubing detail is out of scale and often warped. One of the kits has the Eduard PE set as well as an article from Fine Scale Modeler on how to scratchbuild the tubular tail out of styrene rod. I'll eventually build that as a regular H-13 or a Bell-47.

The other kit had a hopelessly warped tail; there were twists and turns all along its length, even in the center section where the engine sits. I had this kit rattling around for a few years until I decided to turn it into a coaxial rotor (similar to the Hiller XH-44) version of the H-13. I have a paper model of the XH-44 and used the design to get ideas for this one.

Here is where I am so far:

Top view with the rotors in place. The interior and the rotors are not glued:


Front view:


Side view:


Front view with figure, for scale:


The rotor span may seem small, but it's slightly wider than the XH-44 span, and the blades are slightly wider. The total blade length is also about 40% greater than on the original H-13.

I covered the rear framework with thin styrene sheet, after I cut away the most warped sections. The pointy tail still has a slight twist to the side.
The rotor assembly and blades are all scratchbuilt. The tan "transmission" is a tank part, but everything else is styrene tubing, sheet and small Gundam detailing parts.
Still to do are the rotor linkage and the interior.

The color is Tamiya IJN gray. I tried painting it yellow, but I had coverage problems and went with the Tamiya, which covered well in one coat.




« Last Edit: October 24, 2010, 06:32:41 pm by frank2056 »

Offline ysi_maniac

  • Kit Surgeon First Class
  • Needs A Life Outside What-If
  • *****
  • Posts: 6188
Re: Bell H13CX Coaxial Helicopter
« Reply #1 on: October 24, 2010, 06:55:13 pm »
Nice! :wub: :wub: :wub: :wub: :thumbsup:
Will die without understanding this world.

Offline Jschmus

  • Needs A Life Outside What-If
  • *****
  • Posts: 3248
    • My Photos
Re: Bell H13CX Coaxial Helicopter
« Reply #2 on: October 24, 2010, 06:59:53 pm »
Not to nitpick, but shouldn't the rotors be facing in opposite directions?  Otherwise they won't cancel each others torque.

Cool model, though.
"Life isnít divided into genres. Itís a horrifying, romantic, tragic, comical, science-fiction cowboy detective novel. You know, with a bit of pornography if you're lucky."-Alan Moore

Offline frank2056

  • Wears a suit and tie when browsing What-If
  • Needs A Life Outside What-If
  • *****
  • Posts: 1259
    • My web page
Re: Bell H13CX Coaxial Helicopter
« Reply #3 on: October 24, 2010, 07:11:33 pm »
Not to nitpick, but shouldn't the rotors be facing in opposite directions?  Otherwise they won't cancel each others torque.

Cool model, though.

I had the lower rotor flipped upside down in the pictures. The two rotors are independent, so they rotate in opposite directions.

Offline John Howling Mouse

  • Man-Ho
  • Needs A Life Outside What-If
  • *****
  • Posts: 9487
  • I confess: I am a plastic model molester.
Re: Bell H13CX Coaxial Helicopter
« Reply #4 on: October 24, 2010, 08:20:49 pm »
All the way 'round cool.
Styrene in my blood and an impressive void in my cranium.

Offline PR19_Kit

  • Closeted Take That fan
  • What-IF SIG
  • Needs A Life Outside What-If
  • *****
  • Posts: 36380
  • Whiffing since the 70s
Re: Bell H13CX Coaxial Helicopter
« Reply #5 on: October 25, 2010, 12:22:47 am »
Neat, the original 'Flying Phonebox'!  :thumbsup:
Any aircraft can be improved by fitting longer wings, and/or a longer fuselage

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

Offline TsrJoe

  • What-IF SIG
  • Needs A Life Outside What-If
  • *****
  • Posts: 2401
Re: Bell H13CX Coaxial Helicopter
« Reply #6 on: October 25, 2010, 04:59:57 am »
looks sweet, itd be neat to put one of those teeny cheapo rc helicopter gearboxes and motor in it so it rotates whilst sitting on the table  :wacko:
... 'i reject your reality and substitute my own !'

IPMS.UK. 'Project Cancelled' Special Interest Group Co-co'ordinator
IPMS.UK. 'TSR-2 SIG.' IPMS.UK. 'What-if SIG.' IPMS.UK. 'Cold War SIG.' IPMS. 'Finnish SIG.', 'Finnoscandia what-if group'

Offline Taiidantomcat

  • Needs A Life Outside What-If
  • *****
  • Posts: 4382
Re: Bell H13CX Coaxial Helicopter
« Reply #7 on: October 25, 2010, 07:46:37 am »
Brilliant! Figure looks good too :cheers:
"Imagination is the one weapon in the war against reality." -Jules de Gaultier

"My model is right! It's the real world that's wrong!" -global warming scientist

An armor guy, who builds airplanes almost exclusively, that he converts to space fighters-- all while admiring ship models.

Offline Tophe

  • Needs A Life Outside What-If
  • *****
  • Posts: 18326
    • my what-if models
Re: Bell H13CX Coaxial Helicopter
« Reply #8 on: October 25, 2010, 08:56:34 am »
funny look! :lol:
[the word "realistic" hurts my heart...]

Offline sandiego89

  • Needs A Life Outside What-If
  • *****
  • Posts: 2910
Re: Bell H13CX Coaxial Helicopter
« Reply #9 on: October 25, 2010, 03:07:00 pm »
Great work.  Nice save from the warped kit. 
Dave "Sandiego89"
Chesapeake, Virginia, USA

RotorheadTX

  • Guest
Re: Bell H13CX Coaxial Helicopter
« Reply #10 on: October 25, 2010, 03:15:44 pm »
Good stuff! Go man, go!

Offline frank2056

  • Wears a suit and tie when browsing What-If
  • Needs A Life Outside What-If
  • *****
  • Posts: 1259
    • My web page
Re: Bell H13CX Coaxial Helicopter
« Reply #11 on: October 25, 2010, 09:38:52 pm »
I have to figure out how to do the linkages, etc. Should I just add some thin lines and a large(er) hub to hide all the details? Or add some representative hinges? I'm not too clear on how coax helicopter rotor heads differ in details from regular helicopter rotor designs. I'm not sure I want to know, or this project will never get finished...

Oh, and I thought I had an original idea. Wrong! While looking up coax rotor designs, I found the Wagner Sky-Trac. Look familiar?

Offline Taiidantomcat

  • Needs A Life Outside What-If
  • *****
  • Posts: 4382
Re: Bell H13CX Coaxial Helicopter
« Reply #12 on: October 25, 2010, 10:51:59 pm »

Oh, and I thought I had an original idea. Wrong! While looking up coax rotor designs, I found the Wagner Sky-Trac. Look familiar?

I thought you did too! How about that?! good news is the rotor head does look more simple than I expected  :cheers:
"Imagination is the one weapon in the war against reality." -Jules de Gaultier

"My model is right! It's the real world that's wrong!" -global warming scientist

An armor guy, who builds airplanes almost exclusively, that he converts to space fighters-- all while admiring ship models.

Offline Doc Yo

  • Scratchbuilds the entire model
  • ****
  • Posts: 640
    • PreCognitive Dissonance
Re: Bell H13CX Coaxial Helicopter
« Reply #13 on: October 26, 2010, 09:02:05 am »
 looks pretty neat so far. I'd say go with the thin lines/larger hub. The rest of the craft is pretty elegant, and
 too much plumbing up top would be a bit distracting.

Offline sotoolslinger

  • hopes to get everything hung today
  • Needs A Life Outside What-If
  • *****
  • Posts: 5382
  • I am now fairly happy with my lower bits
Re: Bell H13CX Coaxial Helicopter
« Reply #14 on: October 26, 2010, 05:12:32 pm »
Extremely neato :wub: :thumbsup: :bow:
I amuse me.
Huge fan of noisy rodent.
Things learned from this site: don't tease wolverine.
Eddie's personal stalker.
Worshippers in Nannerland